A biochemical treatment device for high COD and high ammonia nitrogen wastewater

Abstract

This utility model relates to the field of wastewater treatment technology and discloses a biochemical treatment device for high COD and high ammonia nitrogen wastewater. It includes an anaerobic tank, a primary A tank, a primary O tank, a secondary A tank, a secondary O tank, and a UF device connected in sequence. A water seal trough is installed at the outlet of the anaerobic tank, and the water seal trough is connected to the primary A tank via a pipe. A gas stirring device is installed at the bottom of the sealed primary A tank, and the gas stirring device is connected to the outlet of a stirring blower. The top of the primary A tank is sealed, and the top of the sealed primary A tank is connected to the inlet of the stirring blower via a pipe. In this utility model, biogas generated by anaerobic digestion is introduced as the carbon source for denitrification in the sealed secondary A tank, improving the utilization rate of carbon sources within the wastewater and saving the cost of external carbon source supplementation. The large amount of heat generated by aerobic biochemical treatment is used to heat the anaerobic circulating influent through a heat exchanger, increasing the temperature of the anaerobic tank while simultaneously decreasing the temperature of the aerobic tank, achieving energy reuse and enabling the system to achieve a "cost reduction and efficiency improvement" effect.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and in particular to a biochemical treatment device for high COD and high ammonia nitrogen wastewater. Background Technology

[0002] High COD and high ammonia nitrogen wastewater, such as landfill leachate, kitchen waste biogas slurry, and livestock and poultry breeding wastewater, has always been a major challenge in the wastewater treatment industry. The prominent problems in the treatment of this type of wastewater are high energy consumption and difficulty in deep or efficient nitrogen removal without an external carbon source. At present, the main treatment methods commonly used at home and abroad are still mainly biological processes.

[0003] Among existing biochemical technologies, anaerobic processes have advantages such as high load, low sludge production, and low energy consumption. However, to achieve good treatment results, anaerobic processes generally require heating the wastewater, consuming a certain amount of heat. Furthermore, the biogas produced by anaerobic processes has a low subsequent utilization rate, with most being directly burned, wasting energy and thus limiting the application of anaerobic processes. In subsequent biological denitrification processes, high sludge concentrations and high organic matter concentrations generate a large amount of biochemical heat during aerobic degradation, requiring circulating cooling water, increasing energy consumption and wasting significant amounts of heat and water resources. Additionally, deep denitrification processes generally require the addition of external carbon sources, further increasing wastewater treatment costs. To address these issues, a biochemical treatment device for high COD and high ammonia nitrogen wastewater is proposed. Utility Model Content

[0004] To overcome the above deficiencies, this utility model provides a biochemical treatment device for high COD and high ammonia nitrogen wastewater, aiming to improve the problems of biochemical heat recovery, biogas utilization and deep denitrification in some high COD and high ammonia nitrogen wastewater in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A biochemical treatment device for high-COD and high-ammonia-nitrogen wastewater includes an anaerobic tank, a primary A tank, a primary O tank, a secondary A tank, a secondary O tank, and a UF device connected in sequence. A water seal trough is installed at the outlet of the anaerobic tank, and the water seal trough is connected to the primary A tank via a pipe. A gas stirring device is installed at the bottom of the primary A tank and is connected to the outlet of a stirring blower. The top of the primary A tank is sealed, and the top of the primary A tank is connected to the inlet of the stirring blower via a pipe. The primary O tank is connected to the primary A tank through a first water passage at the bottom. The primary O tank is equipped with a first nitrification liquid return pump and a second nitrification liquid return pump. The secondary A tank is connected to the primary O tank through a second water passage at the bottom, and the secondary O tank is connected to the secondary A tank through a third water passage at the bottom.

[0007] As a further description of the above technical solution:

[0008] The anaerobic tank inlet pipe is equipped with a system inlet pump and a heat exchanger. The anaerobic tank circulation pipe is equipped with an anaerobic circulation pump, and the outlet of the anaerobic circulation pump is connected to the outlet of the system inlet pump. A water distribution system is provided at the bottom of the anaerobic tank, and the water distribution system is connected to the heat exchanger. The first nitrification liquid return pump is connected to the first stage A tank, and the outlet pipe of the first nitrification liquid return pump is equipped with two bypasses, which are respectively connected to the heat exchanger to achieve heat exchange, thereby achieving the purpose of heating the anaerobic tank and cooling the aerobic tank.

[0009] As a further description of the above technical solution:

[0010] The second nitration return pump is connected to the first-stage A tank via a pipeline, and a cooling tower is installed on the pipeline.

[0011] As a further description of the above technical solution:

[0012] The top of the secondary A tank is sealed with a gas chamber, which is connected to the inlet of the biogas blower through a pipe. The bottom of the secondary A tank is equipped with a biogas aeration system, which is connected to the outlet pipe of the biogas blower.

[0013] As a further description of the above technical solution:

[0014] The secondary A tank is equipped with a methane detector, a hydrogen sulfide detector, and a pressure sensor.

[0015] This utility model has the following beneficial effects:

[0016] 1. In this utility model, by adopting anaerobic pretreatment, the load and energy consumption of subsequent A / O biochemical treatment can be significantly reduced. By introducing biogas generated by anaerobic treatment as the carbon source for denitrification in the secondary A tank, the utilization rate of carbon source in wastewater is improved, saving the reagent cost of external carbon source supplementation. At the same time, the A tank is aerated and stirred by the aeration equipment of biogas and denitrification tail gas, which not only ensures sufficient mixing reaction effect, but also maintains a suitable denitrification environment, thereby improving denitrification efficiency.

[0017] 2. In this utility model, a large amount of heat generated by aerobic biochemical treatment is used to heat the anaerobic tank through a heat exchanger, thereby increasing the reaction temperature of the anaerobic tank while decreasing the temperature of the aerobic tank. At the same time, the nitrification liquid return pump and the anaerobic circulation pump are used as heat exchange circulation pumps, without the need for additional power pumps, reducing equipment configuration and investment, and realizing the reuse of energy and the reduction of power consumption of the treatment system.

[0018] 3. In this utility model, a biogas regulating tank is set on the top of the anaerobic digester. Through storage and regulation, the stability of the biogas outflow can be significantly improved, the land occupied by biogas treatment facilities can be reduced, and the surrounding environment can be improved. Attached Figure Description

[0019] Figure 1 This is a cross-sectional plan view of the present invention;

[0020] Figure 2 This is a schematic diagram of the process flow of this utility model.

[0021] Legend:

[0022] 1. Anaerobic digester; 1.1 System inlet pump; 1.2 Anaerobic circulation pump; 1.3 Water distribution system; 1.4 Water seal tank; 1.5 Biogas regulating storage tank; 1.6 Water seal tank; 1.7 Biogas blower; 2. Primary A digester; 2.1 Gas stirring device; 2.2 Stirring blower; 2.3 Water passage hole; 3. Primary O digester; 3.1 First nitrification liquid return pump; 3.2 Second nitrification liquid return pump; 3.3 Water passage hole; 4. Secondary A digester; 4.1 Biogas aeration system; 4.2 Methane detector; 4.3 Hydrogen sulfide detector; 4.4 Pressure sensor; 4.5 Water passage hole; 5. Secondary O digester; 6. UF device; 7. Heat exchanger; 8. Cooling tower. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Reference Figures 1 to 2 One embodiment provided by this utility model:

[0025] Raw water, pressurized by the raw water inlet pump 1.1, mixes with anaerobic circulating water pressurized by the anaerobic circulation pump 1.2 and enters the heat exchanger 7. After being heated by the heat exchanger, it flows into anaerobic tank 1 through the water distribution system 1.3. In anaerobic tank 1, the organic matter in the wastewater is decomposed by anaerobic microorganisms, producing biogas and other substances. The treated wastewater flows through the water seal tank 1.4 and then through a pipeline into the primary A tank 2. In primary A tank 2, under anoxic conditions, denitrifying bacteria utilize the organic matter in the wastewater to reduce nitrate nitrogen and nitrite nitrogen to nitrogen gas. The effluent then exits through the bottom... The wastewater enters the primary O tank 3 through the water passage, where nitrifying bacteria oxidize the ammonia nitrogen in the wastewater into nitrate nitrogen. The effluent from the primary O tank 3 flows into the secondary A tank 4 through the bottom water passage. In the secondary A tank 4, denitrifying bacteria use methane from biogas as a carbon source to reduce the nitrate nitrogen in the wastewater into nitrogen gas. The effluent from the secondary A tank 4 flows into the secondary O tank through the bottom water passage, further removing residual organic matter in the wastewater. Then, it is pumped into the UF device by the UF inlet pump for sludge-water separation. The clear liquid is discharged, and part of the concentrated liquid is returned to the primary A tank 2, while part is discharged as excess sludge.

[0026] The inlet pipe of anaerobic tank 1 is equipped with a heat exchanger, which uses the large amount of heat generated by the subsequent aerobic treatment to heat the anaerobic inlet water. This increases the anaerobic reaction temperature while decreasing the aerobic reaction temperature, ensuring that both anaerobic and aerobic reactions occur within a suitable temperature range, thus saving energy.

[0027] The bottom of the anaerobic digester 1 is equipped with a water distribution system to ensure that the wastewater and microorganisms are fully mixed. The top of the anaerobic digester is equipped with a biogas regulating tank, which is connected to the top of the anaerobic digester to collect biogas. The biogas regulating tank can regulate the biogas flow rate to ensure the stability of subsequent biogas utilization, while also reducing the footprint of the biogas system. After passing through a water seal tank, the biogas is pressurized by a biogas blower and then enters the subsequent treatment system. The entire anaerobic digester is completely sealed, and the surrounding environment is good. The effluent from the anaerobic digester is equipped with a water seal trough to prevent biogas leakage.

[0028] The external agitator of the primary A tank pressurizes the denitrification exhaust gas generated at the top of the tank. Then, a jet or perforation system is used to agitate the wastewater in the primary A tank, ensuring thorough mixing of the wastewater and microorganisms. The entire primary A tank is completely sealed, ensuring a good anoxic environment and providing excellent conditions for denitrification. It also improves the surrounding environment. A pressure sensor and discharge pipe are installed at the top of the primary A tank to control the replenishment of gas and the discharge of exhaust gas according to the gas pressure, ensuring safety.

[0029] The primary O tank is equipped with a first nitrification liquor return pump and a second nitrification liquor return pump, which return the nitrification liquor to the primary A tank to replenish nitrate nitrogen. The first nitrification liquor return pump also serves as the heat circulation pump of the heat exchanger, heating the anaerobic influent and lowering the temperature of the nitrification liquor. The second nitrification liquor return pump also serves as the cooling tower circulation pump, cooling the nitrification liquor and further lowering the aerobic biochemical temperature. This ensures that the aerobic system can carry out biochemical reactions at a suitable temperature, reducing the need for cooling equipment and saving energy.

[0030] The secondary A tank utilizes a biogas blower to deliver biogas into the wastewater. A jet aeration, microporous aeration, or perforation system is used to aerate and mix the wastewater, ensuring thorough mixing of biogas and wastewater. Denitrifying bacteria use methane from the biogas as a carbon source for denitrification. The resulting exhaust gas is sent to the intake section of the biogas blower for recycling, improving biogas utilization and saving on exhaust gas treatment costs. The entire secondary A tank is sealed, ensuring a favorable anoxic environment and providing excellent conditions for denitrification while also improving the surrounding environment. A methane detector, hydrogen sulfide detector, and pressure sensor are installed at the top of the secondary A tank to control gas supply and exhaust gas emissions based on gas pressure.

[0031] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A biochemical treatment device for high COD and high ammonia nitrogen wastewater, characterized in that: The system includes an anaerobic tank (1), a primary A tank (2), a primary O tank (3), a secondary A tank (4), a secondary O tank (5), and a UF device (6) connected in sequence. A water seal trough (1.4) is installed at the outlet of the anaerobic tank (1), and the water seal trough (1.4) is connected to the primary A tank (2) via a pipe. A gas stirring device (2.1) is installed at the bottom of the primary A tank (2), and the gas stirring device (2.1) is connected to the outlet of a stirring blower (2.2). The top of the primary A tank (2) is sealed. The first-stage A tank (2) is connected to the air inlet of the stirring blower (2.2) via a pipe at the top. The first-stage O tank (3) is connected to the first-stage A tank (2) via the first water passage hole (2.3) at the bottom. The first-stage O tank is equipped with a first nitrification liquid return pump (3.1) and a second nitrification liquid return pump (3.2). The second-stage A tank (4) is connected to the first-stage O tank (3) via the second water passage hole (3.3) at the bottom. The second-stage O tank (5) is connected to the second-stage A tank (4) via the third water passage hole (4.5) at the bottom.

2. The biochemical treatment device for high COD and high ammonia nitrogen wastewater according to claim 1, characterized in that: The anaerobic tank (1) is equipped with a system water inlet pump (1.1) and a heat exchanger (7) on the water inlet pipe. The anaerobic tank circulation pipe is equipped with an anaerobic circulation pump (1.2), and the outlet of the anaerobic circulation pump (1.2) is connected to the outlet of the system water inlet pump (1.1). The bottom of the anaerobic tank is equipped with a water distribution system (1.3), and the water distribution system (1.3) is connected to the heat exchanger (7). The first nitrification liquid return pump (3.1) is connected to the first stage A tank (2), and the outlet pipe of the first nitrification liquid return pump (3.1) is equipped with two bypasses, which are respectively connected to the heat exchanger (7) to achieve heat exchange and achieve the purpose of heating the anaerobic tank and cooling the aerobic tank.

3. The biochemical treatment device for high COD and high ammonia nitrogen wastewater according to claim 1, wherein the top of the anaerobic tank (1) is provided with a biogas regulating storage tank (1.5), and the bottom of the biogas regulating storage tank (1.5) is connected to the top of the anaerobic tank (1) to collect biogas generated by anaerobic digestion. A water seal tank (1.6) and a biogas blower (1.7) are sequentially arranged on the gas outlet pipe of the biogas regulating storage tank (1.5).

4. The biochemical treatment device for high COD and high ammonia nitrogen wastewater according to claim 1, characterized in that: The second nitration liquid return pump (3.2) is connected to the first-stage A tank (2) via a pipeline, and a cooling tower (8) is installed on the pipeline.

5. The biochemical treatment device for high COD and high ammonia nitrogen wastewater according to claim 1, characterized in that: The top of the secondary A tank (4) is sealed with an air chamber, which is connected to the inlet of the biogas blower (1.7) through a pipe. The bottom of the secondary A tank (4) is equipped with a biogas aeration system (4.1), which is connected to the outlet pipe of the biogas blower (1.7).

6. The biochemical treatment device for high COD and high ammonia nitrogen wastewater according to claim 1, characterized in that: The secondary A tank (4) is equipped with a methane detector (4.2), a hydrogen sulfide detector (4.3), and a pressure sensor (4.4).

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